WO2022152126A1

WO2022152126A1 - Button cell having safety device and manufacturing method for button cell

Info

Publication number: WO2022152126A1
Application number: PCT/CN2022/071378
Authority: WO
Inventors: 周显茂; 赵裕锋
Original assignee: 广东维都利新能源有限公司
Priority date: 2021-01-12
Filing date: 2022-01-11
Publication date: 2022-07-21
Also published as: CN112736279A

Abstract

Disclosed in the present invention are a button cell having a safety device and a manufacturing method for the button cell. The button cell comprises a cell, one end of the cell is provided with a positive tab, the other end of the cell is provided with a negative tab, one end of the positive tab is provided on a lower housing, one end of the negative tab is provided on an upper housing, an accommodating cavity is formed between the upper housing and the lower housing, an electrolyte is provided inside the accommodating cavity, a gasket is further provided between the upper housing and the lower housing, a safety device is provided on the positive tab or the negative tab, the safety device is connected to the positive tab or the negative tab in a soldered mode to form a first solder joint, insulating protective glue is provided on the outer side of the first solder joint, the safety device is provided inside the cell, and the cell and the safety device are both soaked in the electrolyte. In the present invention, the safety device is provided inside the cell and becomes an inseparable component of the cell, so that the safety performance of the button cell can be improved, it is convenient for a user to use the button cell, and the button cell can pass a safety test.

Description

Button-type battery with safety device and method of making the same

technical field

The invention relates to the technical field of lithium ion button batteries, in particular to a button battery with a safety device and a manufacturing method thereof.

Background technique

Lithium-ion batteries have the advantages of high voltage, high specific energy, many cycles of use and long storage time. They are not only widely used in portable electronic devices such as mobile phones, digital cameras and laptop computers, but also widely used in electric vehicles, electric In terms of large and medium-sized electric equipment such as bicycles and power tools, the requirements for the electrical performance and safety performance of lithium-ion batteries are getting higher and higher, and polymer lithium-ion batteries are more and more popular due to their excellent performance and excellent safety performance. .

However, in the process of actual use, there are still battery safety issues, especially when the external protection circuit PCM fails, there is a high current charge and discharge or the external circuit is directly short-circuited, the instantaneous high current causes severe heating inside the battery, resulting in Fire, or even explosion and other safety accidents.

In view of the above problems, a lithium ion battery tab with a thermistor has appeared, but the thermistor of the tab is usually provided outside the battery cell. During the safety test, the thermistor located outside is often cut off as an accessory safety component of the cell, resulting in test failure.

technical solutions

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned defects in the prior art, and to provide a button-type battery with a safety device and a manufacturing method thereof. The safety device is installed inside the battery core and becomes an integral part of the battery core, It can not only improve the safety performance of the button battery, it is convenient for customers to use, but also can pass the safety test.

In order to achieve the above purpose, the present invention provides a button-type battery with a safety device, including a battery core, one end of the battery core is provided with a positive electrode lug, the other end is provided with a negative electrode lug, and one end of the positive electrode lug is installed on the bottom. On the shell, one end of the negative electrode ear is installed on the upper shell, a accommodating cavity is formed between the upper shell and the lower shell, an electrolyte solution is installed inside the accommodating cavity, and there is also a gap between the upper shell and the lower shell. Equipped with a sealing ring, it is characterized in that a safety device is installed on the positive electrode lug or the negative electrode lug, and the safety device is welded and connected with the positive electrode lug or the negative electrode lug to form a first welding point, and the outside of the first welding point is The insulating protective glue is installed, the safety device is installed inside the battery core, and both the battery core and the safety device are immersed in the electrolyte.

Preferably, the safety device is a thermistor or an overcurrent resistor.

Preferably, the thermistor or the overcurrent resistor is an embedded rod thermistor or an overcurrent resistor.

Preferably, the diameter of the thermistor or the overcurrent resistor is between 0.5mm-4.0mm, and the height is between 2.0-6.0mm.

Preferably, one end of the safety device is fixed on the upper shell or the lower shell by welding, and internal or external welding is adopted.

Preferably, the welding method is laser or resistance welding.

The present invention also provides a method for manufacturing the aforementioned button-type battery with a safety device, comprising the following steps:

Step S1, the battery core is made by winding, and the center of the wound battery core has a hollow through hole of more than 0.8 mm;

Step S2, the safety device is a rod-type PTC thermistor, and the lower end of the PTC thermistor and the negative terminal of the cell are connected by laser or resistance welding, and then the PTC thermistor is inserted into the wound cell. in the hollow through hole;

Step S3, applying insulating protective glue to the first solder joint formed after welding;

Step S4, welding the positive electrode ear to the lower case by laser or resistance welding;

Step S5, inject electrolyte between the upper shell and the lower shell, install the sealing ring between the upper shell and the lower shell and complete the sealing;

In step S6, one end of the PTC thermistor is fixedly connected to the upper case by external welding to form a second welding point, and the specific welding method is resistance welding.

beneficial effect

In the present invention, a safety device is installed on the positive electrode or the negative electrode. The safety device is installed inside the battery core and becomes an integral part of the battery core. When the button battery is used, when the external circuit is normal or When the internal temperature of the cell is normal, the resistance value of the safety device is very small and can be ignored; when the external circuit is short-circuited or the internal temperature of the cell is too high, the resistance value of the safety device will increase sharply , cut off the current loop inside the cell to prevent high-current charging or discharging inside the cell, so as to avoid overheating of the cell, protect the cell, and improve the safety of high-current charging and discharging of the cell and short circuit of the external circuit It is also convenient for customers to use, and it can pass the safety test.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic cross-sectional structure diagram of a button battery with a safety device provided by the present invention.

Included in the diagram are:

1-cell, 2-positive lug, 3-negative lug, 4-safety device, 5-first solder joint, 6-insulation protective glue, 7-upper shell, 8-lower shell, 9-electrolyte, 10- Sealing ring, 11- the second welding point.

Embodiments of the present invention

The technical solutions in the present embodiment of the present invention will be described clearly and completely below with reference to the accompanying drawings in the present embodiment of the present invention. Obviously, the described embodiment is an embodiment of the present invention, but not all of them. this embodiment. Based on the present embodiment of the present invention, all other present embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Example 1

Referring to FIG. 1 , the present invention provides a button-type battery with a safety device, including a battery cell 1 , one end of the battery cell 1 is provided with a positive electrode lug 2 , and the other end is provided with a negative electrode lug 3 . 2 or the negative electrode ear 3 is provided with a safety device 4 .

Further, if the safety device 4 is installed on the positive electrode lug 2, one end of the positive electrode lug 2 is connected to the battery cell 1, the other end is connected to the safety device 4, and the other end of the safety device 4 is fixedly connected to the lower shell 8 by welding. And form the second solder joint 11; Similarly, if the safety device 4 is installed on the negative electrode ear 3, one end of the negative electrode ear 3 is connected to the battery cell 1, the other end is connected to the safety device 4, and the other end of the safety device 4 is connected. It is fixedly connected with the upper shell 7 by welding and forms a second welding point 11 .

The safety device 4 is welded and connected to the positive electrode lug 2 or the negative electrode lug 3 to form a first welding spot 5, and an insulating protective glue 6 is installed on the outside of the first welding spot 5, and the insulating protective glue 6 can be a pole lug Glue to insulate and protect the first solder joint 5 , and the insulating protective glue 6 can prevent the positive electrode lug 2 or the negative electrode lug 3 from jumping over the safety device 4 to be directly connected together.

The safety device 4 is installed inside the battery cell 1 and is an integral part of the battery cell 1. Further, the safety device 4 is a thermistor or an overcurrent resistor. When the button battery is used, When the external circuit is normal or the internal temperature of the cell 1 is normal, the resistance value of the safety device 4 is very small and can be ignored; when the external circuit is short-circuited or the internal temperature of the cell 1 is too high, the safety device The resistance value of 4 will increase sharply, which will cut off the current loop inside the battery cell 1 to prevent high current charging or discharging inside the battery cell 1, thereby avoiding overheating of the battery cell 1, achieving the function of protecting the battery cell 1, and improving the The safety of battery 1 high-current charging, discharging and external circuit short-circuit is also convenient for customers to use, and it can pass the safety test.

One end of the positive electrode lug 2 is installed on the lower shell 8, one end of the negative electrode lug 3 is installed on the upper shell 7, and a sealing ring 10 is also installed between the upper shell 7 and the lower shell 8, and the upper shell 7 and the lower shell 8 form an accommodating cavity, the interior of the accommodating cavity is equipped with an electrolyte 9, the battery cell 1 and the safety device 4 are both immersed in the electrolyte 9, and the safety device 4 has become a battery cell. An integral part of 1, which is not an accessory component of battery 1, the safety device 4 cannot be removed or taken out without destroying battery 1, and it can directly pass the safety test.

Further, the thermistor or overcurrent resistor is an embedded rod thermistor or overcurrent resistor, which can be directly inserted into the cell 1, and the diameter of the thermistor or overcurrent resistor is 0.5mm-4.0 mm. mm, the height is between 2.0-6.0mm.

Further, the thermistor is a PTC thermistor, the room temperature resistance of the PTC thermistor is 3-20 mΩ, and the resistance value at 85°C is 10-2500 Ω.

One end of the safety device 4 is fixed on the upper shell 7 or the lower shell 8 by welding. If the safety device 4 is installed on the positive electrode ear 2, the end of the safety device 4 can be fixed on the lower shell 8. The safety device 4 is installed on the negative electrode ear 3, the end of the safety device 4 can be fixed on the upper shell 7, the safety device 4 and the upper shell 7 or the lower shell 8 can be fixed by internal or external welding, so The welding method is laser or resistance welding.

Embodiment 2

Referring to FIG. 1 , the second embodiment of the present invention provides a method for manufacturing a button battery with a safety device as described in the first embodiment, including the following steps:

Step S1, the battery core 1 is made by winding, and the center of the wound battery core 1 has a hollow through hole of more than 0.8 mm;

Step S2, the safety device 4 is a rod-type PTC thermistor, the lower end of the PTC thermistor and the negative lug 3 of the cell 1 are connected by laser or resistance welding, and then the PTC thermistor is inserted into the coil. around the hollow through hole of the battery core 1;

Step S3, applying insulating protective glue 6 to the first solder joint 5 formed after welding;

Step S4, welding the positive electrode lug 2 to the lower shell 8 by means of laser or resistance welding;

Step S5, inject the electrolyte 9 between the upper shell 7 and the lower shell 8, install the sealing ring 10 between the upper shell 7 and the lower shell 8 and complete the sealing;

Step S6, one end of the PTC thermistor is fixedly connected to the upper shell 7 by external welding to form a second welding point 11, and the specific welding method is resistance welding.

The second embodiment is only a method for manufacturing the button-type battery with a safety device described in the first embodiment, not all methods. The safety device 4 can also adopt other shapes, and the welding method can also adopt laser welding.

The above manufacturing method is simple to operate, greatly improves the manufacturing efficiency of the button battery, and improves the production quality of the button battery.

To sum up, the beneficial effects of the present invention are:

The safety device 4 is installed on the positive electrode lug 2 or the negative electrode lug 3 of the present invention. The safety device 4 is installed inside the battery cell 1 and becomes an integral part of the battery cell 1. When the button battery is used , when the external circuit is normal or the internal temperature of the cell 1 is normal, the resistance value of the safety device 4 is very small and can be ignored; when the external circuit is short-circuited or the internal temperature of the cell 1 is too high, the safety The resistance value of the device 4 will increase sharply, which will cut off the current loop inside the battery cell 1 to prevent a large current from being charged or discharged inside the battery cell 1, thereby preventing the battery cell 1 from overheating and protecting the battery cell 1. It improves the safety of high-current charging, discharging and external circuit short circuit of cell 1, which is convenient for customers to use, and can pass the safety test.

Claims

A button-type battery with a safety device, comprising a battery cell (1), one end of the battery cell (1) is provided with a positive electrode lug (2), the other end is provided with a negative electrode lug (3), and the positive electrode lug ( 2) One end is mounted on the lower shell (8), one end of the negative electrode lug (3) is mounted on the upper shell (7), and an accommodation cavity is formed between the upper shell (7) and the lower shell (8), An electrolyte (9) is installed inside the accommodation cavity, and a sealing ring (10) is also installed between the upper shell (7) and the lower shell (8). It is characterized in that the positive electrode lug (2) Or a safety device (4) is installed on the negative electrode lug (3), the safety device (4) is welded and connected with the positive electrode lug (2) or the negative electrode lug (3) to form a first welding point (5), and the first welding point (5) is formed. An insulating protective glue (6) is installed on the outside of a solder joint (5), the safety device (4) is installed inside the battery core (1), and the battery core (1) and the safety device (4) are both immersed in Inside the electrolyte (9).

2. A button battery with a safety device according to claim 1, characterized in that, the safety device (4) is a thermistor or an overcurrent resistor.

3. A button battery with a safety device according to claim 2, wherein the thermistor or the overcurrent resistor is an embedded rod thermistor or an overcurrent resistor.

4. The button battery with safety device according to claim 3, wherein the diameter of the thermistor or the overcurrent resistor is between 0.5mm-4.0mm, and the height is between 2.0-6.0mm between.

5. A button battery with a safety device according to claim 1, characterized in that, one end of the safety device (4) is fixed on the upper shell (7) or the lower shell (8) by welding, and an internal or external welding.

6. The button battery with a safety device according to claim 5, wherein the welding method is laser or resistance welding.

7. A method for making a button-type battery with a safety device as described in any one of claims 1 to 6, characterized in that, comprising the following steps:

Step S1, the battery core (1) is made by winding, and the center of the wound battery core (1) has a hollow through hole of more than 0.8 mm;

Step S2, the safety device (4) is a rod-type PTC thermistor, the lower end of the PTC thermistor and the negative lug (3) of the cell (1) are connected by laser or resistance welding, and then the PTC thermistor is connected. The thermistor is inserted into the hollow through hole of the wound cell (1);

Step S3, applying insulating protective glue (6) to the first solder joint (5) formed after welding;

Step S4, welding the positive electrode lug (2) to the lower shell (8) by means of laser or resistance welding;

Step S5, inject the electrolyte (9) between the upper shell (7) and the lower shell (8), install the sealing ring (10) between the upper shell (7) and the lower shell (8) and complete the sealing ;

In step S6, one end of the PTC thermistor is fixedly connected to the upper shell (7) by external welding to form a second welding point (11). The specific welding method is resistance welding.